Abu Zubair (may Allah have mercy on him) says that I asked Sayyiduna Jabir (may Allah be pleased with him) about the issue of keeping a dog, so he replied that Sayyiduna Ibn Umar (may Allah be pleased with them both) informed me that the Prophet (peace and blessings be upon him) said: "Whoever keeps a dog, two qirats are deducted from his reward every day."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5393
Hadith Gradingحکم دارالسلام:إسناده ضعيف ، لضعف ابن لهيعة ، وقد سلف بإسناد صحيح برقم: 4479 بلفظ: «من اقتنى كلبا ليس بضار ولا كلب ماشية نقص من أجره كل يوم قيراطان» .